KZ550 Rejet? Confused...

Howdy ya'll

I did search and I'm a little more on top of things, but the information went a little over my head too.

I just bought this bike (82 KZ550) and it runs alright but it has a problem that I found elsewhere on the site. When I am cruising, I have to turn the choke on for it to smooth out - which, if I have it right, means it is running lean.

Well, that is understandable, since two of the carb boots are missing to the airbox. I am about to order some pods for it. I would just get the boots, but the two that were in there made me quite angry trying to put them in when I cleaned the carbs.

Anyway, it doesn't look that hard to rejet.

I've seen a couple posts on what I need, but I'm not even sure where to start. I know cars pretty well, but am completely new to motorcycles.

I *think* the exhaust is aftermarket, but it is not a 4 into 1 or anything. Just FYI.

So, I just need to rejet, and I don't have to change my pilot jets or re-shim anything just for pods?

Where do I get the jets and do I need to figure out what carbs I have exactly or are they all the same for that year and model?

I saw a really good post about it having to do with comparisons of different bikes and what they needed, and it said you can't just "jump a step" or some other preset formula - you have to do different things for different carbs, etc...

Any helps is appreciated, and anything I left out I would be glad to provide.

Thanks!

That bike uses TK-22 (Teikei) carbs. The stock jets should be 92 mains, and 32 pilots. With pods and stock exhaust, you'll want at least 94 or 96 mains, but 98 aren't out of the question. With pods, I haven't found a strong need for bigger pilot jets.

With aftermarket exhausts and pods you will probably want 98 to 102 mains and most likely the pilots should be around 36 to 38, to reduce choke time.

Obviously, work your way up in steps. Make sure the fuel levels are even, the carbs are balanced, etc.

Also, before any carb work, you need to do a compression test. Check the valve clearance. Then check the ignition.

These are very very rough guidelines. Drilling jets are pretty easy, and that's what I do. Hobby centers usually have really tiny drill bits if you search the internet for hobby chops and tool stores you'll find appropriate bits. The cheap "Tool Shop" drills at Menards have chucks that close down all the way to hold the tiny bits. Luckily, there are rebuild kits out there that come with main jets in case you botch one. You can use small Keihin main jets as replacements if you can find them. I'm not sure if Keihin pilot jets will work, though.

I think the ignition is good, I replaced the plug wires yestrerday because one looked like it had a pinhole in it.

If anyone is looking for them, magnacore plug wires for a DSM engine seem to work well - you can make all the wires out of the two longest wires.

Well, I'll check the valves and compression and if all is good then I'll drill out the jets to 94s then and see if that does the trick. I'm not sure how much, if anything the aftermarket exhaust is doing. They aren't loud or anything - it is pretty quiet actually (which I prefer).

Thanks a lot for the quick reply.

If I am reading that right, if I have to step up to 98s then I'm going to have to start looking at 36 for pilots, right? So, go to 96 if necessary and then start looking at bigger pilots too...

Thanks again!

Right, but don't worry too much about the idle jets right away. I've run up to 102 mains with stock pilots. The big difference is that you'll have to run the choke longer until it really warms up.

Try the mains, adjust the mixtures (air screws, so "out" is leaner, "in" is richer). Start with about 3/4 to 1 turn out. You don't want to go much less than 1/2 turn out. I think 1-1/4 is normal for stock setup.

Also, look into removing the smog related stuff on top of the engine (but don't throw it away). It can lead to backfiring if it's malfunctioning. You can remove it, and plug EVERYTHING it's connected to.

Do not plug the crankcase cover on the transmission. That should get a big, unobstructed tube to the ground or a filter device.

Thanks a lot!

I put the pods on today and then rejetted the carbs. I couldn't find the damn metric drills that small - but a machinist friend of mine had some standard ones. I drilled all of them out to .037 which is right about .94 mm

I just did it by hand - I figured the bit would have broke under power.

Anyway, it made a huge difference, definitely a different bike now and I don't have to mess with stuff going down the road.

Unfortunately, I need clutch disks... and this was made readily apparent now that I actually have some power. 4 is OK, 5 is blah, and 6 is bad.

Clutch Fiber Discs are ready available thru www.denniskirk.com and just replacing them with newer springs should do you well. let the discs sit in oil overnight before installing them.

Any pic's of this bike of yours? Remember, we're all friends here.

Lou is not only a master of the '81 GPz's but great with electronic's as well. Voltron. :woohoo:

CC... PERSONALLY, since you can reuse the clutch cover gasket if it is pretty new, I would put new plates in WITHOUT swapping springs. New springs make for sore wrists... almost all of them are heavier than the originals and pull hard. I LIKE somewhat worn springs as long as the clutch isn't slipping with good clutch disks.

Buy factory friction disks. The aftermarket ones require the stiffer springs, and as WG said, they are PAINFUL. With stock springs, the aftermarkets will slip. I wasted a whole bunch of time on the after market disks trying to figure out what I did wrong to make it slip. Then I called three different speed shops I know near me. They all said get actual Kawasaki disks. They were right. The factory disks grab nicely and the factory springs are nice and light.

To be honest, I have never bought clutch disks. I have a pretty large stack of used disks and if a clutch starts slipping and I can't adjust it out, I have measured all the disks in the stack to ensure they are within spec and eyeballed them for flatness and just use some disks out of the stack. I didn't know that the heavier springs were needed with aftermarket plates. I can get both Versah plates and springs... loud... which type plates did you use that required heavy duty springs... btw: The standard Versah springs are considered "heavy duty" and I have used some of these and they pull harder than stock springs...

I believe they were Vesrah friction disks (from Dennis Kirk). The shops I asked said it didn't matter which brand they were, if they are not Kaw factory parts they are "junk" (their words, not mine). They were very emphatic about it. I've had the factory clutch for 4 years now. Not only did it fix the slippage of the aftermarket clutch, but it also cured the difficulty finding neutral.